function permutations ( start, end ) { var start2 var end2 if ( start.length == 1 ) print(end+start) else { for(var i=0; i<start.length; i++) { start2 = start.substring(0,i)+start.substring(i+1) end2 = end+start[i] permutations(start2,end2) } } } permutations( 'ROMA', '' )